FNB not able to email their customer

After holding on 15 minutes for a call center agent to take my call I was advised FNB is not able to email me a settlement letter, I have to attend to a branch. I advised the agent that it’s not acceptable and asked to speak to a team leader or manager. She responded they are in meetings. I explained that when a customer is not satisfied and insists on speaking to a manager they have to be able to call them out of a meeting, as I work for another bank I know it must be possible. She very rudely responded that she works for FNB and I will not speak to a manager. She refused to provide her surname when I confirmed this will become a formal complaint if it is not resolved. A big financial institution must surely be able to send an email.